The invention is in general directed toward providing a safety lock feature for gymnasium bleachers. More specifically, the invention is directed to providing a wheel channel guide-lock assembly at the lower wheel channels of bleacher rows to prevent lateral, vertical or horizontal displacement. Even more particularly, the invention is directed toward providing a retrofit guide lock assembly for existing manual or power operated telescoping bleachers at each bleacher row.
The invention was made in the course of seeking to solve problems with in-place bleacher collapses of defectively installed or maintained prior art manually or power operated telescoping bleachers. The need for the invention was prompted by a rash of injuries from bleacher collapses, perhaps caused by improper maintenance or incorrect operation of numerous installed bleachers, particularly those school gymnasium bleacher systems installed approximately ten to fifteen years before this invention. The United States Consumer Product Safety Commission, through its Office of Information and Public Affairs, has promulgated a warning with regard to the problems with these types of bleachers. The Commission advised that such telescoping bleachers should be inspected for damage, wear and misalignment and that they should be inspected and maintained in accordance with the manufacturers' operating manuals provided to the purchaser.
Usually, manual or power operated telescoping bleacher assemblies include row locks that trip upward automatically and hold each bleacher row in place until returned to the stacked position. The row locks operate by gravity when the bleachers are extended and typically seat into horizontal wheel channel tabs to lock the particular bleacher row in place and keep the bleacher row secure while spectators sit on the bleacher seats. When the row locks become bent, disconnected, or otherwise not engaged properly, bleacher safety is compromised in misalignment. Binding of the bleachers can occur while the bleacher section is being operated. Effective row locks should be repaired and replaced as these occurrences are detected. But in the past, such has not been the case and it became important that a solution to the resulting bleacher defects be found by means of a retrofit assembly that is useful for various manufacturers' bleacher systems of the telescoping wheel-channel type.
It is noteworthy that manufacturers have instructed the purchasers of bleacher systems to use two people to manually extend the bleachers in order to prevent racking, which is an uneven extension of the bleacher rows and supports. If bleachers become racked, they can lead to serious damage to understructure support channels, braces, and connections. Also, adjoining ends of wheel channels for each row of bleachers are typically provided with finger locks on each channel for engagement to prevent collapse. If they become broken or missing, the adjoining rows will misalign and harmfully bend or possibly crack weld and gusset connections. Usually welds between channels and supporting columns for the rows are provided at gussetted joints therebetween. Welds may also crack should racking or misalignment occur, which causes the channel guides to bind against one another or be displaced away from each other and from the intended telescoping paths of travel. The greatest danger is caused when the locking fingers fail to properly engage whereby the front end, or toe, of a wheel channel guide tips upward. Then, the upper end of the attached column is caused to rotate out of alignment and damage connections to the joint weld at the upper connection to the seat assembly above.
These and other modes of failure are known in the industry and have been serious concerns, due to the number of accidents and injuries to spectators that have occurred and may potentially occur.
As a result, it is a primary goal of the invention to provide a wheel channel guide-lock assembly usable at the wheel channels of telescoping bleacher systems to retain the wheel channels and prevent lateral, vertical and horizontal displacement.
It is a further goal of the invention to provide for such an assembly that may be retrofitted into previously installed systems, such as those sold under the brand names Brunswick, Vecta or Interkal, which comprise bleacher systems primarily installed about ten to fifteen years ago across the United States.
It is a further goal of the invention to provide a wheel channel guide-lock assembly that accommodates uneven floor conditions to securely retain the wheel channels and prevent collapse.
It is an allied goal of the invention to provide a wheel channel guide-lock assembly that may be used in a variety of telescoping bleacher systems, wherein sequential rows of bleachers have wheel channel guides providing rolling support along the floor and which telescope, and slidingly move past each other, from a stacked position to an extended position for use.
It is also an object of the invention to provide a wheel channel guide lock assembly that may be used for originally manufactured telescoping bleacher systems in order to provide a safe and secure means to prevent bleacher collapse and minimize structural damage from racking, shifting or excessive torsion at structural member joint connectors and the like.